Compound hydraulic motor with telescoping pistons



Sept. 2, 1952 HALLER 2,608,826

COMPOUND HYDRAULIC MOTOR WITH TELESCOPING PISTONS Gttornegs J. HALLERSept. 2, 1952 COMPOUND HYDRAULIC MOTOR WITH TELESCOPING PISTONS Filed001'.. 20, 1947 '7 Shee'cs-Sheerl 2 Gttorneg 5 J. HALLER Sept. 2, 1952COMPOUND HYDRAULIC MOTOR WITH TELESCOPING PISTONS Filed 001'.. 20, 19477 Sheets-Sheet 3 FC5. "z

Gttornegs J. HALLER Sept. 2, 1952 coMPoUND HYDRAULIC MOTOR, WITHTELEscoPING PIsToN 7 Sheets-Sheet 4 Filed' 001'.. 20, 1947 Snventor J.HALLER Sept. 2, 1952 COMPOUND HYDRAULIC MOTOR WITH TELESCOPING PISTONSFiled Oct. 20, 1947 '7 Sheets-Sheet 5 Egg/5f @141.

S'pt- 2, 1952 J. HALLER 2,608,826

poMPouND HYDRAULIC MOTOR WITH TELEscoPING PIsToNs Filed oct. 2o, 1947 7sheets-sheet e J. HALLER Sept. 2, 1952 COMPOUND HYDRAULIC MOTOR WITHTELESCOPING PISTONS 'i' sheets-sheet 7 Gttomegs 211 6 28 l'muentor FiledOct. 20, 1947 Patented Sept. 2, 1952 UNITED STATES PATENT orticaCOMPOUND HYDRAULIC MOTOR WITH TELESCOPING PISTONS 3 Claims. 1

This invention relates to molding machines and processes'. and inparticular to such machines and processes for making articles bycompressing powdered materials, such as powdered metals and theiralloys.

One object of this invention is to provide an improved machine formaking powdered metal bushings according to a, sequence of-operations,and enabling a flange, either internal or external, to be formed uponthe bushing.

Another object is to provide a machine for making flanged bushings frompowdered metal wherein the powdered metal is loaded into a die andtubular telescoping plungers are reciprocated Vto compress the powderedmetal and form the flange on the bushing. Y

Another Objectis to provide a machine for molding ilanged bushings frompowdered metal ywherein tubular outer and inner forming plungers arecaused to reciprocate in opposite directions toward one another, thereciprocation of the outermost or innermost pistons being terminated ata distance from one another equal to the thickness of the flange desiredon the bushing, depending on whether the ange is to be formed on theoutside or onthe inside of the bushing.

Another object is to provide a machine for molding iianged bushings frompowdered metal, as set forth in the preceding objects,` wherein thevarious forming plungers of the machine are actuated by hydraulic motorscontrolled by a hydraulic circuit.

Another object is to provide a process of making anged bushings ofpowdered metal, wherein the powdered material of the bushings iscompressed from opposite directions in zones at-diierent distances fromthe central axis, the compression being halted in the outermost orinnermost zone at a'predetermined separation of the oppo- Figure 3 is aside elevation of the lower portion of the machine shown in Figure 1,with a portion thereof in section; A 1

Figure 4 is a side elevation of the upper portion of the molding machineshown in Figure 2;

Figure 5 is a fragmentary rear elevation, partly in section, oftheportion of the machine included by the ybracket in Figure 3 and lookingin the direction of the arrow 5 therein; p n

Figure 6 is an enlarged horizontal section along the line 6-6 in Figure1;

Figure 7 is a horizontal section alongthe line 'i-'l in Figure 3 showingthe powdered metal loading or charging mechanism;

Figure 8 is a fragmentary vertical section along the line 8 8 in Figure7;

Figure 9 is an enlargement ofthe lower portion of Figure 1, showing thisportion of the'machine in more detail;

Figure 10 is an enlargement of the central portion of Figure 1, showingthe portion ofthe machine immediately above that shown in Figure A9;

Figure 11 is a horizontal section along the 'line Ill-I I in Figure 10;

Figures 12 s to 17 inclusive are fragmentary central vertical sectionsof the upper portion of the machine shown in Figure 1, showingdiagrammatically the positions of the'lnoving parts in the vsequence ofoperations performed 'in molding a ilangedbushing of powdered metal; jY' Figure 18 is a perspective YView of a powdered metal'bushirigproduced by the machineiand process of thisinvention; Y A

Figure 19 is a hydraulic circuit diagram showing an operating andvcontrol system adapted to be used lwith the machine and' processy ofthe present invention,V with certain portions of the machine shown invertical section;

Figure 20 is a longitudinal section through a four-way Valve similar tothat used for controlling the hydraulic circuit of Figure 19, but withthe various conduits and ports arranged in a single plane, forsimplifying the showing Figures 21 to 26 inclusive' are fragmentarycentral vertical sections lof the upper portion of the machine shown inFigure 1, showing diagrammatically the successive positions of themoving parts in the "sequence of operation performed `in molding ailanged bushing of powdered metalof modified form whereinA the viange ison the outside of one end of the bushing; v. l i Figures 27 1:01733inclusive are fragmentary central verticall sections of the upperportionof the machine shown Yin xFigure` 1 ,1 showing diagram'v matically thesuccessive positions-of the moving parts in the sequence ofoperationperformed-in molding a langed'bushing of. powdered` metal aoftheinside of one end of the bushing; i Figure -34 is a perspective Viewof-aimo'died further modied form wherein the-ange ison powdered metalbushing produced by the machine and process of this invention wherein anexternal ange is formed on one end of the bushing by the operationsshown diagrammatically in Figures 21 to 26 inclusive; and

Figure 35 is a perspective view of a further modied powdered metalbushing produced by the machine and process of this invention wherein aninternal ange is formed in the bushing by the operations showndiagrammatically in Figures 2'1 to 33 inclusive.

General arrangement In general, the molding machine of the presentinvention includes a series of concentrically-arranged molding plungersreciprocating vertically in opposite directions relative to a fixed diewith a bore therein. Reciprocating horizontally across the top of thedie is a mold charging device or `riller shoe Vfor feeding the powderedmetal to the mold or die from -a vertical hopper. The various plungers,some of which are tubular, and the iiller shoe are moved through theirvarious cycles of operation by means of hydraulic motors includingreciprocating pistons and cylinders. The supply of pressure fluid iscontrolled by several four-way valves.

Molding machine construction The molding machine, generally designatedI0, ofthepresent invention (Figures 1 to 4 inclusive) is supported by abed or base I I and head i2 interconnected by strain rods I3 withreduced diameter end portions I4 entering corresponding bores .I5 in thebase and head II and I2, and terminating in nuts I5 threaded upon theends ofthe reduced diameter portions I4.

Mounted on the strain rods I3 and secured thereto as at I1 is a diesupport I8. The latter is provided with bores I1a through which thestrain rods vI3 pass. The die support I3`(Figures 1 and 8) in turncontains a central bore or die barrel 'I9 having an'en'largedcounterbore 20 at its upper end. The bore I3 and counterbore 2G receivea sleeve-like die V2| (Figure 8) having a flanged portion 22 tting intothe counterbore 20. The die 2I contains a central bore 23 in whichreciprocates a lower outer tubular plunger '24. The latter in turn isprovided with a bore 25 in which reciprocates an inner tubular plunger26. 'The tubular plunger 26 contains a central longitudinal bore 21 inwhich reciprocates a core rod 28 in the form of a solid plunger.The'connections and actuating `mechanisms for the concentric or co-aXialplungers 24, 26 and '28 are described below in more detail. o

Co-operating with 'the lower plungers VM, 26, and 28 and co-axialtherewith are two upper tubular plungers 29 and 3i respectively (Figure8). The upper outer-'tubular plunger 29 has a diameter the same as thelower outergtu'bular plunger 24 and is likewise adapted to enter andtisnugly but reciprocably within the die bore 23. The plunger -ZS'has abore 30 therein of the same diameter as the bore 25 in the plunger 24(assuming that the upper and lower portions of The bushing, generallydesignated 33 (Fige ure 18) of powdered metal which is made in themachine and by the process of the present invention, consists of asleeve 34 having a bore 35 extending longitudinally through the centerthereof. The sleeve 34 has a lower portion 36 and an upper portion 31with an annular flange portion 38. The upper and lower portions 31 and35 are assumed to be of the same diameter, but might obviously be ofdifferent diameters if such were called for by the form of the bushing.The diameters of the sleeve portions 36 and 31 are determined by thediameters of the bores 25 and 33 (Figure 8) within the lower and upperouter tubular plungers 24 and 29 and the diameter of the flange portion38 is determined by the diameter of the die bore 23. The length of thebushing 33 between its lower and upper ends 39 and 43 (Figure 18) isdetermined by the closest distance of approach of the inner tubularplungers 23 and 3I (Figure 15) whereas the thickness of the 'flangeportion 38 is determined by the distance of approach of the lower andupper outer tubular plungers 24 and 29. The diameter of the bore 35through the bushing 33 is determined by the diameter of the core rod 28.

The feeding, charging or lling mechanism for loading the die 22 with itspowdered material, such as powdered metal, is shown in Figures 3 4, 7and 8. The powdered material is contained in a downwardly-taperinghopper 4I which is mounted on and secured as at 42 to the head I2 oftheY machine I0 (Figure 4). Connected to the spout-like lower end 43 ofthe hopper 4I is a flexible pipe 44 the lower end of `which (Figures 3and ,8) is connected to and seated in the annular recess 45 at the upperend of the passageway 4E in a charging deviceor filler shoe 41. Thepas'- sageway '45 opens into a chamber 48 in an enlargement 43 inwhichvthe'shoe 41 terminates. The Vlower end 5l) of the shoe 41 is openand is slidable smoothly over the upper surfaces 5I and 52 of the die 2land die su-pport I8 respectively. The Tiller shoe 41 reciprocateshorizontally from the positions shown in Figures 8 and 14 to 1'1inclusive to the position shown in Figure 12, in order to deposit acharge of powdered material, such as powdered metal, in the die bore 23and the associated cavities in the various tubular plungers 24, 26, 29and 3 I.

The mechanism by which the filler shoe Il-'I is moved to-and-i'ro in theabove manner is shown in Figures 1 and 8, and is mounted in part uponthe `die support I and in part upon an angle bracket 53 bolted as-at 54to the side ofthe die support i8 (Figure 8). Bolted to the upper sur'-iace 55 of. the angle braoket53 are the spaced heads A56 and 51 Aof .ahydraulic cylinder 58, the latter having a bore 59 thereinwhichreciprocably receives the piston head 60 connected to the pistonrod 5I. The cylinder heads 5B and 51 are provided respectively withchambers 462 vand 63 from which ports '64 and `(55 open outward (Figure7 these in turn being connected` to conduits 66 and 51 forsupplyingpressure iiuid to the cylinder 58 or forexhausting ittherefrom.

The cylinder head 55 contains a longitudinal yborei (Figure 8)V throughwhich the piston rod 6I passes and in which it reciprocates. The outerend of the piston rod l6I is secured bythe pin 10 in l a bore 1 I formedin a. downwardly-extending arm 12 integral with a plate-like webg13`which forms a crosshead supporting the filler shoe '41, the latter beingintegralwith the web 13.

The web or crosshead 13 at its opposite ends (Figure *7) is provided:with cylindrical bosses 14 having parallel guide bores 1'5. The bores1-5 slid- 'ably engage tubular guide rods 16 which are parallel to oneanother and have their opposite ends mounted in bores 11 and 18 in theupper ends of forward and rearward arms 19 and 80 extending upward inopposite directions from base plates 8| (Figures `'7 and 8) bolted tothe upper surface 52 of the die support |8.

The upper outer and inner tubular plungers 29v and 3| are reciprocatedby mechanism contained within the hydraulic cylinder '82 (Figures 2 and4) mounted in a bore 83 in the head. The cylinder 82 which constitutesan outer cylinder, is closed at one end by a cylinder head 84 (Figure 2)which has a central bore 85 and a counter- --bore 86 equipped with apacking (not shown) and a gland 81 for compressing this packing. Thecylinder head 84 is also provided with a port 88 -passing therethroughand connected at its outer end to a conduit 89.

Passing through the bore 85 and gland 81 is `a. hollow stem 90containing iluid passageways 9| and 92. Immediately inside the outercylinder 82 `adjacent the cylinder head 84, the stem `90 is enlarged toform an inner cylinder head 93 which is, in'eiect, the end of a hollowpiston head. The head I93 closes the top of an inner cylinder 94, thelower end of which is closed by the enlargement 95 on the upper end ofla hollow rod or plunger 96. Secured as at 91 to the lower end of thehollow rod 96 (Figure 2) is an upper platen 98. The inner cylinder 94,which in effect forms the side wall of a hollow piston head, re-

ciprocates in an outer cylinder bore 99, access to the upper end ofwhich is gained by the port -the piston |02 is thus reciprocated, itcarries with it the hollow stem 90. `Connection to the passageways 9|and '92 of the stem 90 is made by flexible pipes |03 and |04 connectedrespectively tothe ports |05 and |06. The hydraulic circuit by whichthese ports are subjected to hydraulic pressure and suction is shown inFigure 19 and described below.

The hollow piston |02 or inner cylinder 94 lthereof is provided with aninternal bore |01 (Figure 2) in which an inner piston head |08 is re-.ciprocable The piston head |08 is connected to a hollow inner piston`rod |09 through which ports II lead to an inner bore The latter in turnleads through a branched passageway I2 toa bore I |3 within the outerpiston rod 96. The

inner piston rod |09 beyond the passageway ||2 lcontinues downward in asolid extension I I 4 (Figure 2) which passes through a reduced diameterbore I| and thence through a counterbore ||6 containing a packing (notshown) compressed by a ring 1, and thence through a bore II8 in theplaten 98. passes through a reduced diameter bore-I I9 and acounterbore|20 also containing a packing (not shown) compressed by an annular glandI2 I. i Secured as at |22 to the platen 98 (Figure 2) is ail'angedtubular support |23 extending downward and having a bore I 24co-extensive with the bore ||8 'and similarly permitting reciprocationvSimilarlythe outer piston rod 96 ofthe extension II4 of the inner pistonrod |09. Secured to'the lower end of the tubular support |23 is anannular end plate |25 (Figures 1 and 8.) havingv a bore |26 throughwhich the inner upper tubular plunger 3| reciprocates. The end plate |25is also provided with an, annular socket |21 (Figure 8) within which theflanged upperend of the outer upper tubular plunger 29 is seated andheld in position by a retaining ring |28 bolted 'as at |29 to the endplate |25. Thus. by they foregoing construction the passageways l92 and'9| in the hollow stem convey fluid to or from the opposite sides of theinner piston head |08 (Figure 2) by way of the ports ||0 and'bore thepassageway I2 serving to drain the bore II3 surrounding the inner pistonrod extension II4.

The outer and inner lower tubular plungers 24 and 26 and thecore rod 28are actuated by hydraulic motors in the form of cylinders and pistonslocated below the die support I8. The base or bed is provided with abore |30 (Figures l and 9) in which is mounted the lower outer cylinder|3| having therein a cylinder bore |32. The lower end of the cylinderbore |32 is closed by a cylinder` head |33 having a port |34 therein towhich is connected a conduit |35. A port |36 opens into the upper end ofthe outer cylinder bore |32 and is connected to a conduit |31. 'Ihecylinder head |33 is also provided with a central bore |38 through whichpasses a lhollow stem |39 provided with passageways |40 and I4I havingports |42 and |43 connected respectively to conduits |44 and |45(Figures 1 and 9). The bore |38 is provided witha counterbore |46containing a packing |41 (Figure 9) compressed by an annular ange |48 toprevent leakage around the stem |39.

Immediately above the outer cylinder head |33, an inner cylinderr heador `piston head. Y|49 is threaded upon the stem |39v (Figure 9). Theinner cylinder |50 is threadedly connected tov the inner cylinder head|49 and is thereby reciprocated yin the outer cylinder bore |32. Theinner cylinder |50 is provided with a bore |5| into the end of which isthreaded the' annular enlargement |52 on the lower end of a hollowpiston rod |53. The piston rod |53 passes througha reduced diameter bore|54 in the upper end of the cylinder |3| and is bolted as at .|55 to thelower platen |56. The bore |54 is provided with a counterbore |51contaninga packing |58 compressed by a gland |59, thereby preventingleak- .age around the' outer piston rod |53. Thus/the inner cylinderhead |49, inner cylinder I50fand enlargement |52 (Figure A9)collectively rforman outer hollow piston |60. Y J

Reciprocable within the inner cylinder bore |5| is an inner piston head|6| connected to ahollow piston rod |62 through which the ports I 63extend into a bore |64 communicating with the passageway |4| andconduit|45. Beyond the bore |64 the branched passageway |65 leads to thereduced diameter bore |65a within the hollow piston rod |53 and in whichthe inner piston rod I 62 reciprocates. Beyond the passageway |65, theinner piston rod |62 continues ina reduced diameter solid extension |66(Figure 9). The latter passes through a further reduced di'- ameter bore|61 Iimmediately above the bore |66 and thence through a counterbore |68containing a packing |69 compressed by a ring or gland |10, therebypreventing leakage around the inner piston rod extension |68.

The inner piston rod extension |66 passes through a hole |1| in theplaten |56. (Figure 9) land :above .the latter is provided withalongitudinal slot |12 (Figures 1 and 10) for the purpose of containing.mechanism for reciprocating the core 'rod 28 as described below. Securedto the .upperend of the `pistonrod extension |66 .as by r-the.retaining'ring |13 and boltsor screws |14, is theiilangedlower'end of.the inner lower tubular plunger 25. The vlatter passes through a bore'|15 in the upper 'end of an elongated support |16 (Figure 10) which isiianged at its lower end and lboltedas at' |`1 to the platen |56(Figures 1 and 9).. 'The support |19 surrounds the piston rod rextension66 and is provided with strengthening webs |18 to increase its rigidity.

The lower end of the lower outer tubular plunger 24 is hanged (Figurel0) and is secured to .the upper end of the support |16 by a splitflanged retaining ring |19 bolted thereto as at |80 (Figure l1). Thering |19 is provided with a gap IBI through which the outer tubularplunger 24 may Ibe inserted, and the top |82 of the elongated support|16 is similarly provided with a slot |83 through which the innertubular piston 26 may :be inserted (Figure l1). The top |02 serves as a'bridge between Athe parallel arms of the elongated support |16 (Figures6 and lil), the piston rod eX- tension |66 reciprocating in the spacebetween these arms.

' The core rod 29 is raised and lowered by a hydraulic motor |843consisting of a hydraulic cylinder |65 with end caps or heads |86 and|81 closing the opposite ends thereof (Figures 3 and i5). The end cap|86 is secured to the underside m|83l of a block |89 which in turn isbolted as at |90 .(Figures .l and 3) to the underside of the die'support I8. The block |89 also contains a pair of spaced vertical boresI9! in which the upper ends of a pair of spaced vertical guide rods |92are secured. The lower endsof the guide rods l|92 pass loosely throughbores |93 in the lower platen |56.

The lowerk cylinder head |31 is bored as at |94: (Figure 5) for thepassage of a piston rod |95 carrying a piston head |96 which isreciprocable in the bore |51 of the cylinder |85. heads '|86 and |81 arebored to receive the ends of conduits |98 and |99 (Figure 3) by whichpressure duid is suppliedto and exhausted from the opposite ends of thecylinder |85.

The lower end of the piston rod |95 is threaded Y asat 200 (Figure 5)and passes through a hole -in'a cross head 25| which is bored at itsends (Figurel) for the-passage of the guide rods |92. .The rcrossr, head20| is held invengagement with The CII

`the lower end' of the piston rod |95 Aby lock nuts 202 threaded on thethreadedportion 200 on opposite .sides of the cross hea-d 29|. Thisconstruction also provides vertical'adjustment for the vcross head 20|relatively to the piston rod |95. The cross head 20| is approximatelycrossshaped and isiprovided with an elongated inwardly projectingportion 256V which passes .through the slot .i12 inthe innerpiston rodex V:tension `|66 and isat that point provided with tively.

esienersae rods |3 onopposite sides of the support |16 in Yparallelrelationship.

Hydraulic circuit Figure 19 shows the hydraulic circuit by 'which 'themachine l0 is controlled and actuated, to-

gether with the principa1 parts of the machine itself as shown in moreldetail in Figures 1 to l0 inclusive. The various hydraulic motorconsisting or" cylinders and pistons have been described above, inconnection with the parts which they operate, together with the conduitsby which pressure iluid is supplied and withdrawn. The

various hydraulic motors are double-acting, that is, reciprocable `inopposite directions merely by supplying pressure uid to one end of thecylinder while exhausting it from the other end and vice versa. Thus,the pistons of the various hydraulic motors are advanced and retractedby reversing the llow pressure iiuid to the opposite `valves such as areshown diagrammatically in Figure 20,V the various ports and conduits ofwhich are placed in a single plane in order to L, simplifyY theirshowing.

The control valve 24|, for example, may consist of-an approximatelycylindrical casing 250 'havinga longitudinal bore 25| in whichreciprocates -a valve vspool 252 having a central head 253 andendflfieaols 1254 and I255. The spool 252 is provided witha transversepassageway 256 through the central head 253 and also with transversepassageways 251 and 258 at the opposite yends thereof outboard of theheads 254 and 255. Between -the heads 254 and v255 and the central "head253 the valve spool 252 is provided with reduced diameter portions 259and 260 respec- A central longitudinal passageway 26| yinterconnects thetransverse passageways 256,

The spool 252 isconnected at one end to a valve rod 262. The `spool 252may, if desired, be provided ,with conventional centering spring (notshown) which normally tend to restore the valve spool`259 to its centralposition shown in Figure 2f).y Y Y Y Y Th'ecasing 256 is provided with acentral pressure 'supply port 256 connected to the conduit y251 whichinwtur-n'is connected to the pressure sideof'a'vhydraulicpump (notshown) or-.other source of pressure fluid. On either side of thepressure! 'fluid supply port 266, the casing 250 `'is provided withpressure iiuid distributing ports 2651and126'9 which are connectedrespectively to the conduitsd'l .and |45. The casing 250 is iinallyprovided with a -longitudinal passageway 210 having end ports 21|l and2,12 opening into the bore 25| adjacent the transverse spool passages251 and 258 when the valve spool 252 is in itsy centra1-position. Thepassageway 21|) leads to a central discharge port 213 which in turn isconnected to a` discharge-or vexhaust conduit 214 by'which the dischargeuid is returned to the tank or reservoir (not shown) which is a commonand usual part of a conventional hydraulic pump circuit. 'Ihe Vvalve rod2652 is connected by a clevis 215 and pin 216 to a hand lever 211, thelower end of which is pivoted at 218 to a bracket 219 secured'to thecylindrical casing 250.

Thus, when the valve rod 262 and valve spool 252 are shifted to the left(Figure 20), pressure uid passes from the conduit 261 through the ports266 and along the reduced diameter portion 259 to and out through theport 268 into the conduit |44. At the same time, uid returning from theconduit |45 escapes through the ports and passageways 269, 256, 26|,258, 212, 219 and 213 into the return or discharge conduit 214 leadingto the tank or reservoir.

When the valve spool 252 is shifted to the right, the port l269 becomesconnected to the pressure fluid Supply port .266 along the reduceddiameter portion 26D of the spool 252, whereas the port 268 becomesconnected to the discharge conduitv 214 by way of the ports and passages256, 26|, 251, 21| and 210.

The control circuit shown in Figure 19 is illustrated as being manuallycontrolled by the various -hand levers 211, this being done forsimplicity of showing. In actual practice, however, in order to make themachine fully automatic, each of the valve rods 262 will be shiftedto-and-fro by a pair of solenoids placed at the opposite ends of eachvalve rod. The energization of the solenoids is selectively controlledby limit switches operated by arms projecting from the various plungersas they reciprocate to-and-fro. This electrical circuit, however, isbeyond the scope of the present invention. 1

Accordingly, for the purposes of operation of the machine, it will beassumed that the hydraulic circuit is manually controlled and that theoperator shifts the hand lever 211 of each of the control valves 24|. to246 inclusive at the proper moments to'cause the respective plungers toreciprocate the desired distances. Obviously, the plungers will bereciprocated different distances according to the dimensions of thebushing 33 to be produced by the machine. The distances to which thevarious plungers may reciprocate can becontrolled by stops or by merelylimiting the distanceto which each plunger can reciprocate within itsrespective cylinders. Obviously, the various plungers may also beprovided with scales and pointers to indicate their motion andterminate'it at the desired point to produce a bushing of the desireddimensions. Thus, when the operation is described, it will be assumedthat by one of these expedients, the operator will terminate thereciprocation of the various hydraulic motors at .the desired points intheir strokes and do this in the proper sequence in the cycle ofoperations aboutto be described.

Operation in, making intermediate-flanged external bushings Beforestarting the machine l0, let it be as- 3 and 4). It will also be assumedthat the various parts of the machine are in the relative positionsshown in Figure 19, where they are ready to begin an operating cycle.Let it further be assumed that the conduit 261 is being supplied withpressure fluid froma suitable source such as a hydraulic pump (notshown) To start the cycle of operations, the operator shifts the handlever 211 of the control valve 244 so that pressure iiuid is dischargedfrom the supply conduit 261 through the valve 244 and out through theconduit 61 into the right-hand end of the cylinder 58 (Figure 19). Thiscauses the piston head 68 and piston rod 6| to move to the lef-t,shifting the charging device orller shoe 41 overY the mouth of the diebore 23 (Figures 8, 12 and 19). Meanwhile, the fluid displaced from theleft-hand end of the cylinder 58 returns to the valve 244 by way of theconduit 66, whence it is discharged through the conduit 214 into thetank.

When the iiller shoe 41 arrives over the die bore 23, particles of thematerial fall into and ll up the space in the bores 23 and 25 (Figure12). The operator causes the charging shoe 41 to dwell in its chargingposition a suflicient length of time to insure that the die bore isproperly charged, whereupon he shifts the hand lever 211 of the controlvalve 244 in the opposite direction. This causes pressure iluid to passfrom the supply line 261 through the valve 244 intok the conduit 66,thence through the port 64 (Figure 19) at the left-hand end of thecylinder 58. 'Ihis causes the piston 6U, piston rod 6| and charging shoe41 to` be retracted from its charging position and shifted to the rightinto the position shown in Figure 19. from the right-hand end of thecylinder 58 Vpasses through the port 65, conduit 61, valve 244 anddischarge conduit 214 into the tank.

The operator now shifts the'hand lever 211 of the valve 245 to causepressure fluid to pass from the supply line 261 through the valve 245and conduit 89 into the upper end of the cylinder' 82 lwhere itA actsagainst the hollow outer piston head 93. This action moves the pistonhead 93 downward, carrying with it the upper platen 98,

then shifts the control valve 245 to its central or neutral position,holding the plunger 29 temporarily in its Figure 13 position.

The operator then shifts the control valve 243 so that pressure iluidpasses through it from the supply line 261 into the conduit |99 andthence into the lower end of the cylinder |84. This forces the piston|96 and piston rod |95 upward carrying with them the cross head 28| andcore rod 2 8. The nuid displaced by the upward motion of the piston head|96 passes from the upper end of the cylinder |84, through the conduit|98 and valve 243 into the discharge conduit 214 and thence back to thetank. The core rod moves upward, pushing aside the particles of powderedmaterial 280 until it enters the bore 30. When the core rod reaches theposition shown in Figure 14, the operator shifts the valve 243 to itsneutral position, holding the corerod 28 in the position shown in Figure14.

The operator also shifts the control valve 24| to admit pressure fluidfrom the supply conduit 261 through the valve 24| and conduit |44 intovThe fluid displaced acca-,sac

the lower-.end of the inner cylinder borev |5I, moving the piston head16| upward and Awith it the plunger-@ and inner lower tubular plunger26. Ihe fluid displaced from the upper end of, the bore |51 passesdownward through the passage-way EAI, conduit iand: valve 221|Y intothedischarge conduit 212. When the inner lower plunger 25 `reaches theposition shown in Figurele, the operator holds' itthere temporarily byshifting the control valve 24| to its neutral position. l

The operator now shifts the' control valves 245 and 2li-$- so. as tocause the upper outer and inner tubular plungers 2d and 37|- to movedownward,` pressure;` fluid being supplied to the-conduits 89 and |03from the pressure fluid supply line 281 andwithdrawn through theconduits ||lI and` |34 respectively intoV the discharge conduits 214.When the upper plungers 29- and 3| have moved downward to the positionsshown in Figure 15, depending upon the dimensions desired for the nishedbushing, the upper inner tubular plunger 3| telescopes with the core rod23 and completely seals oilthe cavi-ty occupied by the-powderedmaterial. f The operator then shifts the control valve 24| again toadmit pressure iiuid tothe conduit M4. and to discharge it from theconduit l'in the'inanner previously described, causing the lower innertubular plunger 26 to movev still further upward into the posi-tionshown in Figure 15. This action further compresses the powdered material288 and forms the bushing 33. to its desired dimensions.

Theoperator now shifts the control valves 225 andA 226 in the mannerpreviously described to admit pressure :duid to the conduit IUI and |04and discharge it from the conduits S9 and |23, thereby raising thepistons 93 and IDB and with them the upper outer and. inner tubularplungers 29 and 3|. The parts now occupy the position shown in Figure16.` ready for ejection of the i molded buishing.r l

To. eject the molded bushing, the operator again shifts. the controlvalve 2i2 to its forward positionwherein pressureilud is delivered totheconduit and discharged from the conduit I3?, moving the lower outertubular plunger 24 upward. until its upper end is flush with the surface5| of thedie support. I8. This action raises the flange. 38 on thebushing to an exposed position clear of the die bore 23i (Figure 16) Atthe same time he shirts the control Valve 2i?! to admit pressure ifluidto the conduit and discharge it from `the conduit Idil, causing thelower inner tubular plunger 26'to move upward.V rthis insures thatthelange 38 and the lower end 39 of the bushing 33 will be pushed upwardatA the samev time.

When the opera-tor has halted the lower outer tubular plunger 24 at thelevel of the surface 5i of the die. support I8 (Figure 16) and hasshifted the control valve l2 to its neutral position, he continues tohold. the control Valve 24| in its forward position, causing the lowerinner tubular plunger 2S to continue tov-move upward until its upperendalso reaches the level of the surface 5I. This action raises thebushing 33- so that its lower end 39 is flush with thel upper surface 5|ofthe die support i8. Meanwhile, the operator shifts the control valve22.3 to its reverse position whereby pressure fluid is delivered to theconduit ISS and is discharged from the conduit |99', moving the pistonhead E92 downward (Figure 19) `and retracting the cross-head 26| andcore rod 23 to the position shown in Figure 17.

12 This action pulls the core rod 23 out of the central bore 35- in thebushing 33 -and enables,v the bushing to be ejected. The bushing 33. isthen subjected to the usual sintering and other finish-` ing operations,forming no part of the present-infV vention. v

To move the parts back intov the position shown in Figure S-ready forthe molding of anotherl bushing 3.3, the operator shifts the controlvalves 24| and 2132 to their reverse positions whereby pressure fluid isdelivered to the conduits |45 and |31 and discharged from the conduitsIMand |135, causing the lower outer and inner tubular plungers 24 and26t0- movedownward to the positions shown in Figure 8'. The operatorthen shifts the Operation in makingl end-flanged external bushing Themodified bushing, generally designated 281|, shown in Figure 34,consists of a body portion or sleeve 282 having a bore 283 extendinglongitudinally through the center thereof. The sleeve 282 has an annularflange portion 284 adjacent oneV endthereo, the lower and upper ends 285land 286 respectively being formed'byv the oppositely-moving lower andupper outer and inner tubular plungers 24', 26, 29, 3| and core rod 28.The sequence of operations in making the modied bushing 28.! isgenerally similar to that 'previously described` above in making theintermediate externally ilanged bushing 33. but diiers in detail.

rlhe die bores 23 and 25V are charged or loaded bymanipulating thecontrol valve 244 (Figure 19) in the manner previously described so asto move the charging shoe lIl over the top of the die bore 23. The shoe4l is held there for a suicienttime to permit the particles of powdercdbronze or other powdered metal to ll the die cavity, whereupon the shoeil is retracted' by reversing the control valve 2li/l. Figure 21 thusCorrespond/s to Figure 12 after the charging shoe, 4l has beenretractedto the position shown in Figures 1s and 19. 'y

lIn the set-up of the machine to produce'V theV anged'bushing 28|,however, vitjis sucient for the purposes of the invention to hold thecore rod;

28 stationary withl its upper .end flush withY the:`

upper outer and inner tubular bushings 29' and 3| are held with theirlower ends flush with one another andare moved up and down as a unit.

With. the parts in the position shown in Figurer2l, the operator nowshifts the control valves 245 and 226 to cause pressure uid to enter theconduits ligand |03 and. be discharged from the conduits IGI and' |02,thereby moving the upper outer and inner plungers 28 and` 3| downward apredetermined depth into the die bore 23 (Figure 22). When this occurs,the upper end of the core rod 2a enters the bore` 32 in the upper innerplunger 3|, sealing the die cavity completely.

With the parts inthe position shown in Figure 22, the operator nowshifts the control valves 24|and- 2&2 to admit pressure fiuid to theconv duitsll and Illll and to discharge uid from the -13 conduits |31and |45, causing the lower outer and inner plungers 24 and 26 to moveupward to the positions shown in Figure 23, partially compressingV thepowdered metal.

Withthe parts in the positions shownin Figure 23," the operator-haltsthe upward motionof the lower outer plunger 2B Foy shifting the controlvalve to neutral, but continues to hold the control valve 24| in itsforward position, causing the lower inner plunger 24 to continue to moveupward. The plunger 24 moves upward, further and finally compressing thepowdered metal and shortening the sleeve portion of the bushing; thecontrol valve 242 being shiftedlto neutral position when the plunger 24reaches the DOSition shown in Figure 24.

With the parts in the positions shown in Figure 24, the operator shiftsthe control valves 245 and 246 to their reverse positions, retractingthe upper outer and inner plungers 29 and 3| to the position shown inFigure 25. He then shifts the control valves 24| and 242 to theirforward positions,causing thelower outer and inner plungers 24 and 26 tomove upwardly simultaneously until the top of the outer plungerZB islevel with the top surface 5| of the die 2 1 Withrthe parts in thepositions shown in Figure 25, the operator then shifts the control valve242 to neutral while holding the control valve .24| in its forwardposition. This ejeots the lbushing 28| from the position shown in Figure25 to that shown in Figure 26. The bushing is then removed and subjectedto the additional processes such as sintering. By then shifting thecontrol valves 24| and 242 to their reverse positions, the

operator retracts the outer and inner plungers 24 and 26 to theirlowered positions shown in Figure 21, whereupon the machine is ready forbeginning a new cycle of operation, commencing with the charging of thedie cavitywith powdered metal by shifting the shoe 41. Y

Operation in making mid-flanged internal Y,

' bushing The modified bushing, generally designated ,281, shown inFigure- 35, consists of a body portion or sleeve .288 having lower andupper ends 239 and 290 respectively and containing a central bore 29|with lower and upper enlargements 292 and 293 respectively. Theenlargements 292 and 293 terminate at shoulders 294 and .295 forming thelower and upper ends of an internal flange 296. The sequence ofoperations in making the modified bushing 281 is generally similar tothat previously described above in making the bushings 33 and 28| butalso differs in detail.

With the 4parts in the positions shown in Fig. 27, the die boore 23 ischarged or loaded in the manner previously described by manipulating thecontrol valve 244 (Figure 19) so as to move the charging shoe 41 overthe top of the die bore 23 long enough to permit the particles ofpowdered metal to flll the die cavity. The shoe is then retracted byreversing the control valve 244, whereupon the parts correspond inposition to those shown in Figure 12. In Figure 27, however, the lowerinner tubular plunger 26 is moved so that its top end is a considerabledistance above the top of the lower outer plunger 24, since the flange29B is to be formed internally rather than externally. The core 28 isalso stationary throughout the entire sequence of operation in makingthe internally-flanged bushing 281. Furthermore, the upper outer andinner tubular plungers 29 and 3| commence operations with theirlowerends flush with one 'an-'l other, as shown in AFigure 27.

With the parts in the positions shownin Figure 27, and with the diecavity 23 charged withf powdered metal and the charging shoe `41retracted, Vthe operator shifts the controlvalves 245 and 246 to theirforward positions in the manner previously described', moving the upperouter and inner 'plungers 29 and 3| downward until their lower ends areflush with the upper" surface 5| of the die 2|. This seals the diecavity 23, as shown in Figure 28. l v

' With the parts in the positions shown in Fig-. ure 28, the operatorreverses the control valve' 24| to retract the lower inner plunger 26 ashort distance while leaving the outer plunger `v24. un-

changed.` He also shifts the control valve 246- to'V its forwardposition while holding the control valve 245 in its neutral position,causingl the upper outer plunger 29 to remain stationary while the innerplunger 3| moves downwardbelow-the' level of the surface 5|, telescopingwith .the iupper end of the core rod 28.' The material ofthe Figure 29.

.bushing is thus partially compressed, as shown. in'

Figure 2 9 Ato the positions shown in Figure further compressing-'thepowdered metalll A. Withthe partszin the positions shown inFigure 30,the operator Yshifts the control valves 245 and 245 to neutral,ho1dingthe upper outer and inner plungers 29 'and 3| 'in' their previously-at'-tained positions. He also holds the control valve" 24| in its neutralposition while shifting the control valve 242 Vto its forward position.This causes the lower outertubular plunger 24 to move up"-V` ward,imparting` the final squeezel'to the` bushing To 'ejectvthe bushing 3|to the positions shown in Figure 32 with the lower ends of theseplungers ush with one another, whereupon he shifts the control valves245 and 24'6 to neutral. He then shifts the control valves 24| to 242 totheir forward positions, causing them to advance simultaneously upwardand eject the bushing 281 from the die cavity 23, as shown in Figure 32.

With the parts in the positions shown in Figure 32, the operator nowreverses the control valve 24| to retract the lower inner plunger 26,freeing it from the bushing 281 and permitting the latter to be removedfrom the machine. The operator then shifts the control valve 242 intoits forward position while holding the control valve 24| also in itsforward position so as to retract the lower outer and inner plungers 24and 26 down to their starting levels shown in Figure 27. The machine isnow ready to commence another cycle of operations by shifting thecontrol valve 244 to advance the charging shoe over the die cavity 23and fill the latter with powdered metal.

What I claim is:

1. A compound hydraulic motor comprising a hydraulic cylinder having anouter bore with axially spaced fluid ports communicating therewith, saidcylinder having an aperture in one end thereof, a hollow outer pistonreciprocably from ythe position shown Yin Figure 31, the operator-shiftsthe control valves 245 vand 246 into their reverse positionsandr'e--ltracts the upper outer and inner plungers 29 and mounted in saidouterbore and having an inner bore therein coaxial with said. outerbore, an outer piston rod connected to said outer piston and extendingexternally of said cylinder, an inner piston reciprocably mounted insaid inner bore and having an aperture therethrough, an. inner pistonrod connected to said inner piston and extending externally of saidcylinder, and an elongated fluid feed member mounted on the centralportion of said outer piston in coaxial relationship therewith andreciprocable bodily therewith, said feed member extending inwardlythrough said inner piston aperture to the inner side of said innerpiston and extending outwardly through said cylinder aperture externallyof said cylinder, said feed member having a pair of fluid passagewaysleading therethrough and opening into said inner bore on opposite sidesof said inner piston.

2. A compound hydraulic motor comprising a hydraulic cylinder having anouter bore with axially spaced fluid ports communicating there-With,'said cylinder having an aperture in one end thereof, a hollowouter piston reciprocably mounted in said outer bore and having an innerboreL therein coaxial with said outer` bore, an outer.- piston rodconnected to said outer piston and extending externally of saidcylinder, an inner piston reciprocably mounted in said inner bore andhaving an aperture therethrough, an inner piston rod connected to saidinner piston and extending externally of said cylinder and anelongated'fluid feed member mounted on the central portion ofl saidouter piston in coaxial relatonship therewith and reciprocable bodilytherewith, said feed member extending inwardly through said inner pistonaperture to the inner side of said inner piston and extending outwardlythrough said cylinder aperture externally of said cylinder, said feedmember having a pairi of uid passageways leading therethrough and;opening into said inner bore on opposite sides of said inner piston,said inner piston rod having-a cavity therein with a port opening fromsaid cavity into said inner bore behind said innerpiston, said feedmember extending into said cavity;

3. A compound hydraulic motor comprising a hydraulic cylinder having anouter bore with axially spaced` uid ports communicating therewith, saidcylinder having an aperture in one: end thereof, a hollow outer pistonreciprocably mounted in said outer bore and having aninner bore thereincoaxial with said outer bore, a tubular outer piston rod connected tosaid outer piston and extending externally of-said cylinder, an innerpiston reciprocably mounted in said inner bore and having an aperturetherethrough, an inner pistonrod disposed within said tubular outerpiston rod in telescoping relationship therewith, said inner piston rodbeing connected to said inner piston and extending externally of saidcylinder, and an elongated fluid feed member mounted on the centralportion of said outer piston in coaxial relationship therewith andreciprocable bodily therewith, said feed member extending inwardlythrough said inner piston aperture to the inner side of said innerpiston and extending outwardly through said cylinder aperture externallyof said cylinder, said feed member having a pair of fluid passagewaysleading; therethrough and opening into said inner bore on opposite sidesof said inner piston.

JOHN HALLER.

REFERENCES orren- The following references are of record inthe file of`this patent:

UNITED STATES PATENTS Stokes et al. Mar. 7, 1950

